6 ;;Quote: every description of an event or position of an object depends on coincidences with a rigid body of reference or, equivalently, a Cartesian system of co-ordinates

15 ;;Quote: motion is relative to a frame of reference; a dropt stone follows a straight line in a stationary frame and a parabolic curve in a moving frame

16 ;;Quote: the restricted principle of relativity is that natural phenomena follow exactly the same laws in all inertial co-ordinate systems

16 ;;Quote: relativity is a general principle that applies with great accuracy to mechanics; it should apply to all physical domains

17 ;;Quote: if special relativity was false, there would be an absolute frame of reference and physical systems would depend on their relationship to the rapidly moving earth; such effects are not seen

26 ;;Quote: simultaneous events in a stationary frame are not simultaneous in a moving frame; even if measure lightning flashes at the midpoint of two locations

31 ;;Quote: the time of an event depends on the event's reference-body or co-ordinate system

33 ;;Quote: since distance measures depend on simultaneous events; length depends on the frame of reference

38 ;;Quote: with the Lorentz transformation, x=ct holds in a stationary frame and the transformed equation, x'=ct', holds in a moving frame of reference

51 ;;Quote: a body which absorbs energy E_0 without changing velocity has the same energy as a body of mass m+E_0/c^2; hence the inertial mass of a system is equivalent to an energy of mc^2

72 ;;Quote: a body in a gravitational field receives an acceleration which is independent of the body's material or physical state

80 ;;Quote: Newton's first law is only valid for inertial frames of reference; why should inertial frames have priority over other frames of reference? Newton saw this objection

90 ;;Quote: in a rotating disk or gravitational field, the speed of a clock depends on its location

99 ;;Quote: a Gaussian co-ordinate system assigns a continuum to each dimension of a Cartesian co-ordinate system

99+;;Quote: a Gaussian co-ordinate system applies to a non-Euclidean continuum if "size" and "distance" are locally Euclidean

108 ;;Quote: the general principle of relativity states that all Gaussian co-ordinate systems are equivalent relative to the general laws of nature; this restricts these laws

128 ;;Quote: by the general theory of relativity, the geometrical properties of space are determined by matter

149 ;;Quote: the frequency that an atom absorbs or emits light depends on its position in a gravitational field, just as a clock on a rotating disk depends on its distance from the center

149+;;Quote: Adams confirmed that spectral lines shift toward red in a strong gravitational field; predicted by Einstein

158 ;;Quote: if a box is at rest inside another box, the two spaces are the same; not true if the boxes move relative to each other

158+;;Quote: there are an infinite number of spaces which are in motion relative to each other

161 ;;Quote: the order of acoustical experiences in time can differ from the order of corresponding visual experiences

161+;;Quote: the time sequence of events is not the same as the time sequence of experiences

164 ;;Quote: in Newtonian mechanics, physical reality was space and time with permanently existing material points and independent observers

172 ;;Quote: a uniformly accelerating frame of reference is indistinguishable from a homogeneous gravitational field; source of the general theory of relativity

176 ;;Quote: if one removes a gravitational field, absolutely nothing remains; neither inertial space nor topological space

176+;;Quote: the gravitational field describes the topological and metrical properties of the manifold

176+;;Quote: an inertial space is a gravitational field with constant space-time functions